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Playback response slow
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the drobo is the thunderbolt connected media drive
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Drobo’s are significantly slower due to the virtual raid they employ. What happens if you use a different drive whether Thunderbolt or internal?
Eric-ADK
Tech Manager
support@adkvideoediting.com -
would adding the flash memory to the drobo help? i’m kind of stuck with it.
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Drobo’s are good for archive but not as work/media drives. The Virtual raid slows down the bandwidth performance and significantly increases latency. Do not use them for work drives. A single Thunderbolt drive would be better in this case. Use the Drobo for archive which is what it’s meant for.
Eric-ADK
Tech Manager
support@adkvideoediting.com -
right. except they don’t make single drives big enough for what I need.
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How big a Media Volume raid do you need?
Add what drives you need to that.
Eric-ADK
Tech Manager
support@adkvideoediting.com -
The Drobo is 5 bay, 4tb each. To describe whats happening: the 2 angles play completely fine in the source monitor. it plays right away, no dropped frames, smooth all around playback. while in the program window, it takes the 2-3 sec to begin playing. so doesn’t the drobo seem fine if it plays great in source?
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Not necessarily. The source monitor is just the player. There are no GPU acceleration elements involved nor caching involved with that. It’s strictly disc read requests to processor decoding and straight to draw out on the screen. When the Program monitor is active now you have the Disc read requests, Decoding from the player, Data buffers to ram for GPU acceleration components, encoding to Mpeg I-frame codec and then draw out on the screen. The entire pipeline is much longer which shows latency problems far more. The drobo latency may not come into play just playing a file back but when you have all of the above processes required to playback along with media cache files for audio then the latency will become an issue. It’s a simple test by just taking the Drobo out of the equation. Use another external drive or an internal drive long enough to test the playback latency on the timeline. See what it’s like. However that Drobo is significantly slower than that 4bay Areca storage unit I listed in the previous post due to that virtual raid. This is well known throughout the IT industry for Drobo’s. Their great for archive but the performance drawback is too much for work drives.
Eric-ADK
Tech Manager
support@adkvideoediting.com -
good to know. ok here’s another question, why does it play fine, once it starts? and secondly, why doesn’t the clip start to play right away if I’m not clicking away from it. just stopping and starting. shouldn’t it be more instant since the drive isn’t searching?
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The Drive is still handling read requests. Remember the Hardware MPE player is buffering frames ahead based on how much ram you have, GPU in the system, and codec of media played along with how many layers. When you hit play it has to start buffering realtime where it left off the last time it cached. It doesn’t wait to cache till the previous cached amount is played through. It immediately starts caching as you play. Other wise your video would stutter every time the cache frame data was played through and it had to completely re-cache again. It’s much more efficient to cache data as you go based on where it left off with the original cache of frames. When you jump the transport to a new area it has to re-cache again completely which is often why it takes up to a few seconds before the program monitor reflects the change to the new start frame. The entire MPE engine ie hardware acceleration player is creating a new cache frame list and building data buffers for the GPU acceleration data. This process takes time and you will see it. Once you hit play though as long as the cache ahead is far enough to give enough time for new frame buffers to be created the editor wont see any drops in playback as this process continues until playback stops.
Eric-ADK
Tech Manager
support@adkvideoediting.com
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